Methods and systems to combine RF ablation therapy with device navigation

Abstract

Methods and systems for combining ablation therapy with navigation of the ablation device. An ablation system may be configured for use with one of two methods to prevent loss of navigation signals during ablation energy delivery. In the first method, ablation energy signals are filtered from the navigation signal. In the second method, the delivery of ablation energy is sequenced with the delivery of navigation energy such that ablation energy and navigation energy are not delivered at the same time and navigation signals received by the system are time-division multiplexed to reconstruct the navigation signals and determine a location of the device within the patient.

What is claimed is: 
     
       1. A method of determining a location of a treatment device during an ablation procedure within a patient, the method comprising:
 delivering ablation energy from an ablation electrode of the treatment device to an area of tissue; 
 delivering navigation energy to a plurality of external patch electrodes from a plurality of navigation energy sources, the navigation energy delivered by each of the plurality of navigation energy sources being a same frequency; 
 transmitting a plurality of voltage signals from a mapping electrode of the medical device to a processing unit, the processing unit time-division multiplexing the voltage signals, wherein the processing unit time-division multiplexes the voltage signals in each of a first plane, a second plane, and a third plane; and 
 determining a location of the medical device within a patient based on the time-division multiplexed voltage signals. 
 
     
     
       2. The method of  claim 1 , wherein the frequency is between 5 kHz and 25 kHz, the method further comprising:
 transmitting a plurality of impedance signals from the mapping electrode of the medical device to the processing unit when the navigation energy is delivered in unipolar mode, the processing unit time-division multiplexing the impedance signals; and 
 transmitting a plurality of impedance signals from the mapping electrode of the medical device to the processing unit when the navigation energy is delivered in bipolar mode, the processing unit time-division multiplexing the impedance signals. 
 
     
     
       3. The method of  claim 1 , wherein the frequency is a between 80 kHz and 120 kHz, the method further comprising:
 transmitting a plurality of impedance signals from the mapping electrode of the medical device to the processing unit when the navigation energy is delivered in unipolar mode, the processing unit time-division multiplexing the impedance signals; and 
 transmitting a plurality of impedance signals from the mapping electrode of the medical device to the processing unit when the navigation energy is delivered in bipolar mode, the processing unit time-division multiplexing the impedance signals. 
 
     
     
       4. The method of  claim 1 , wherein delivering ablation energy from the ablation electrode of the treatment device is during an on period and the delivering of ablation energy stops during an off period. 
     
     
       5. The method of  claim 4 , wherein the navigation energy sources are alternating current sources, and wherein the alternating current sources are configured to deliver alternating current electricity to each of the external patch electrodes at the same frequency. 
     
     
       6. The method of  claim 1 , wherein the navigation energy sources are alternating current sources, and wherein the alternating current sources are configured to deliver alternating current electricity to each of the external patch electrodes at the same frequency. 
     
     
       7. The method of  claim 1 , wherein the delivered ablation energy is pulsed electric field energy. 
     
     
       8. A method of determining a location of a treatment device during an ablation procedure within a patient, the method comprising:
 delivering ablation energy from an energy generator to an ablation electrode of the treatment device to an area of tissue; 
 delivering navigation energy to a plurality of external patch electrodes from a plurality of navigation energy sources, the navigation energy delivered by each of the plurality of navigation energy sources being a same frequency; 
 filtering the delivery of the ablation energy and the delivery of navigation energy using a first filter that is applied to an input of the navigation energy sources, the first filter allowing navigation energy to pass between the treatment device and the plurality of navigation energy sources while presenting a high impedance and preventing the ablation energy from entering the plurality of external patch electrodes; 
 transmitting a plurality of voltage signals from a mapping electrode of the medical device to a processing unit, the processing unit time-division multiplexing the voltage signals, wherein the processing unit time-division multiplexes the voltage signals in each of a first plane, a second plane, and a third plane; and 
 determining a location of the medical device within a patient based on the time-division multiplexed voltage signals. 
 
     
     
       9. The method of  claim 8 , wherein the plurality of navigation energy sources are three alternating current energy sources that deliver energy at three separate frequencies. 
     
     
       10. The method of  claim 9 , wherein the three separate frequencies are each at least 30 kHz, the three separate frequencies being delivered to the external patch electrodes. 
     
     
       11. The method of  claim 8 , wherein the first filter is a band-reject filter that matches the frequency of the delivered ablation energy. 
     
     
       12. The method of  claim 11 , wherein the band-reject filter matches at least one of the following frequencies 460.8 kHz and 100 kHz. 
     
     
       13. The method of  claim 8 , further comprising:
 filtering the delivery of ablation energy from the energy generator with a second filter that is at the energy generator to prevent the ablation energy from interfering with the navigation energy. 
 
     
     
       14. The method of  claim 13 , wherein the second filter is a band-reject filter that matches the frequency of the delivered navigation energy.